Temperature sensitivity of bat antibodies links metabolic state of bats with antigen-recognition diversity

The bat immune system features multiple unique properties such as dampened inflammatory responses and increased tissue protection, explaining their long lifespan and tolerance to viral infections. Here, we demonstrated that body temperature fluctuations corresponding to different physiological states in bats exert a large impact on their antibody repertoires. At elevated temperatures typical for flight, IgG from the bat species Myotis myotis and Nyctalus noctula show elevated antigen binding strength and diversity, recognizing both pathogen-derived antigens and autoantigens. The opposite is observed at temperatures reflecting inactive physiological states. IgG antibodies of human and other mammals, or antibodies of birds do not appear to behave in a similar way. Importantly, diversification of bat antibody specificities results in preferential recognition of damaged endothelial and epithelial cells, indicating an anti-inflammatory function. The temperature-sensitivity of bat antibodies is mediated by the variable regions of immunoglobulin molecules. Additionally, we uncover specific molecular features of bat IgG, such as low thermodynamic stability and implication of hydrophobic interactions in antigen binding as well as high prevalence of polyreactivity. Overall, our results extend the understanding of bat tolerance to disease and inflammation and highlight the link between metabolism and immunity.


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For most of the experiments collected sera samples were pooled.Each bat serum pool consist of sera obtained from 3-10 individuals.
Exceptionally some experiments with N. noctula were performed by using a large pool (35 individuals).The pools were performed for practical reason as the collection of only small volumes of blood from bats is feasible.Our goal was that pool contain samples from identical individuals in terms of gender, age, physiological status.Birds sera pools consisted of serum of 2-4 individuals.
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The study did not require blinding.The effect was validated by applying alternative experimental approaches and by using two different species.
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April 2023 Flow Cytometry

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